Trundle for making quick-assemble mobile shopping bag

ABSTRACT

A disposable mobile shopping bag that can be readily assembled, and can bear loads well is. The mobile shopping bag is composed of an ordinary shopping sack, a disposable platform insert and press-fitting wheel assemblies. When opened the sack accommodates the inserted platform on base of the sack interior. The platform has press-fitting holes in positions appropriate for holding the wheel assemblies. Press-fitting mounts project from the tops of the wheel assembly forks. To put the mobile shopping bag together, the press-fitting mounts are pressed against the exterior of the bottom of the sack over the respective holes in the platform, into which they are then inserted.

This application is a continuation-in-part of U.S. application Ser. No.09/254,665, filed Mar. 15, 1999, now abandoned which was the NationalStage of International Application No. PCT/ES98/00167, filed Jun. 10,1998.

BACKGROUND OF THE INVENTION

1. Technical Field

The present invention relates to mobile shopping bags; in particular theinvention relates to shopping bags that, distinct from bag carriers, arethemselves mobile for wheeled portage of consumer purchases.

2. Description of Related Art

Consumers in shopping centers and supermarkets often find themselveswith bulky. purchases such as food and cleaning items that they need totransport some considerable distance by hand, and yet are without apersonal handcart. This is most likely because they either do not own orwish to own a handcart, which is rather unwieldy, or do not wish to orhave forgotten to bring one along.

To address the problem of a ready means for towing shopping bags heavywith purchases, a disposable shopper's cart, for example, has long sincebeen proposed. U.S. Pat. No. 2,868,557 to Klipp and Abramson disclosessuch a cart. The disposable shopper's cart is formed of a single sheetof a stiff material such as cardboard, and is assembled by first foldingup longitudinal rear and flanking lateral walls, which interlock bytabs. Wheels are then secured to the cart body, either on a single axlepassing along the rear inside corner, or on a pair of stub axles eachlocked into the respective rear corners.

Clearly, the assembled disposable shopper's cart as described in theKlipp and Abramson patent has drawbacks in how the assembled cart bearsweight on the wheels. Wherein a long axle carries the wheels, the axleis liable to bend, impeding the mobility of the cart; the stub axleswould bear weight better, but are liable to rotate out of true,destabilizing the cart's mobility.

Moreover, the cart as taught by Klipp and Abramson requires fasteningretaining cords to the cart body in order to hold a shopping bag in thecart.

U.S. Pat. No. 3,197,225 to Powell recognizes the foregoing problems andcontemplates a hand-portable, collapsible shopping cart with rigid baseplates and unilateral wall plates for withstanding heavy loads. Ashopping cart embodied according to the Powell disclosure is fashionedfrom durable materials including a fabric bag and plates of aluminum,and is clearly not designed to be disposable. Furthermore, the shoppingcart as claimed and taught by Powell in the principal embodimenttrundles on unilateral rolling means (ball casters) mounted on a beveledsurface of the bottom plate to keep the casters out of the way when thebag is opened and set down for loading. The ball casters are fixed tothe beveled surface “by riveting, bolting, welding, pin-clenching or thelike.” The configuration essentially has the wheels mounted at thevertex where the bottom and side plates of the cart join.

Collapsible shopping carts described by Powell thus are neithermass-producible nor disposable, and the cart must be tilted onto therolling means before the cart is mobile.

A collapsible, wheeled base assembly to which a large bag may beattached is disclosed in U.S. Pat. No. 4,596,397 to Conti. To assemblethe device for use as a mobile shopping bag, a large sack such as agarbage bag is folded into a pleat around the bottom of the opened bagfor insertion into pin-and-cap fittings at the corners of the baseassembly. This operation would seem awkward to accomplish, although thedisclosure does mention that the bag may be cemented to the base.

As taught in the Conti patent, the pair of wheels is mounted to the baseon horizontally extending axles. The base is designed with a wingconformation to strengthen its rigidity, and presumably the bag-and-baseassembly trundles more stably than the cart described in the Klipp andAbramson patent. Nevertheless, not only does the mobile shopping bagassembly described by Conti seem bothersome to assemble, but it alsoseems that in use the pleats in the bag clenched by or cemented onto thebase assembly would undergo strain that could rend the bag.

Accordingly, a mobile yet disposable shopping bag that can be readilyassembled by the user or pre-assembled by the merchant is desirable.Disposability is desirable since even if consumers own portable shoppingcarts they often tend not to bring them on shopping trips. Shoppers tendnot to anticipate every instance in which their purchases become suchthat they wish to have mobile bag if one is at hand.

SUMMARY OF THE INVENTION

An object of the present invention is to configure a mobile shopping bagthat is made of disposable materials, that can be readily assembled, andthat can bear weight well and is easily trundled when assembled.

The present invention is embodied principally by a disposable platforminsert, which may be foldable, having press-fitting recesses or holes inpositions appropriate for holding wheels; at least two disposable wheelassemblies comprising press-fitting mounts projecting from the tops ofwheel-carrying forks; and a conventional, disposable sack that whenopened accommodates the platform insert in the base of the sack.

To put the mobile shopping bag together, accordingly, the sack is openedand the platform insert is placed inside the bag on the base. Thepress-fitting mounts on the wheel assenblies are then pressed againstthe exterior of the bottom of the sack over the respective holes orrecesses in the platform, into which they are then inserted.

Depending on the configuration of the platform/press-fitting mounts, andthe sack material, this operation may or may not puncture the bottom ofthe sack. In either case, clenching the material on the base of the sackin the press fitting between the wheel mounts and the platform securesthe wheel assemblies to the platform through the sack.

The platform for embodying the present invention can be shaped toconform to a variety of shopping sacks depending on the form of the baseof the sack when opened. The arrises (sharp edges) on the platform arerounded to reduce the chance of the sack being torn by the platform.

Since a mobile shopping bag embodied in accordance with the presentinvention is disposable and can be quickly assembled, it is readilyavailable to the consumer otherwise without means to cart bulky ornumerous purchases. The mobile shopping bag is thus spares shoppers whomust hand-transport their purchases home or otherwise over longdistances the trouble of having manually to bear weighty and numerousbags, helping to alleviate a source of back and hand pain.

The foregoing and other objects, features, aspects and advantages of thepresent invention will become more apparent from the following detaileddescription in conjunction with the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is an oblique drawing representing a typical sack for holdingconsumer purchases;

FIG. 2 is a view of the underside of a platform insert;

FIG. 3 is an enlarged view of a press-fitting wheel assembly;

FIG. 4 depicts the wheel assembly press-fitted through a sack into ahole in a corner of the platform insert, shown in section;

FIG. 5 is an oblique view corresponding to FIG. 4, with the platformindicated in phantom inside a fragmentary representation of the sack;and

FIG. 6 is an elevational view depicting an assembled mobile shopping bagin an embodiment of the present invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

The configuration of the present invention is such that it may, beembodied using any of a variety the sacks that typically hold shoppingitems. FIG. 1 depicts an example of a shopping sack 1 for embodying theinvention. A bottom-end fold 1 a is formed in the sack such that whenthe sack is opened it will have a base. The fold 1 a may also be apleat, and may be between 25-30 cm. long as a typical example.

In the present invention, nonetheless, the applicable sack need not befreestanding on the base. Accordingly, the sack suitably may be made ofplastic, cloth, paper, or stiffer material such as cardboard. On theother hand, a sack with the bottom end fold 1 that holds its shape whenopened facilitates introduction into the sack of a platform insert 2,described next, in putting together a mobile shopping bag embodying theinvention.

A non-limiting feature of the present invention is that the upperportion of the sack composing the disposable mobile shopping bag mayhave openings 1 b through which the hands can be introduced, functioningas handles. This region may include a reinforcement made as a foldedpart of the sack material itself, or may be of a reinforcement material.Alternatively, the sack may be made simply with handles.

FIG. 2 shows a representative conformation of the platform insert 2 towhich the wheels of the mobile shopping bag of the present invention aremounted. The platform insert 2 is made of a disposable material, andoptionally may be foldable. Fabricating the platform insert 2 out ofplastic or other synthetic resin-containing material, for example, wouldserve in making the platform 2 disposable as well as foldable. In thedepicted embodiment, the platform 2 is about 24×40 cm.

Holes 3 in the bottom of the platform insert 2 are shaped to receivepress-fitting mounts on wheel assemblies, which are described later. Atleast two holes 3 are provided, on the longitudinal center of theplatform 2, for example. FIG. 2 depicts the platform 2 embodied withfour holes near the rounded respective corners 6 of the platform 2.

The platform insert 2 optionally may be adhered or otherwise joined inadvance to the interior that becomes the base of the sack when opened.In particular, when thus embodying the invention with the platforminsert 2 joined in advance to the sack interior that forms the bottom ofthe mobile bag, if the platform 2 is foldable, the sack and platform 2combination may be folded compactly for packaging.

Ribs 4 indicated in FIG. 2, or like reinforcements are providedcrisscrossing the platform insert 2 for strengthening it in weightsupport. Material-saving recesses 5 assume a geometric figure, and canform the ribs. The platform 2 is thus designed according to the physicaland mechanical properties of the material used, such that it may supportloads of as much as 20-40 kg. or more.

The wheel assembly 7 depicted in FIG. 3 is composed chiefly by apress-fitting mount 8, a fork 9, and a wheel 10 on an axle 11, all ofwhich are fabricated from disposable materials, such as those containingsynthetic resins.

The axles 11 may be retained by end covers, or may be press-fitted intoappropriate holes in the ends of the fork 9. Optionally, the wheel 10and the axle 11 may be formed integrally of the same disposablematerial. The wheels 10 may be hollow or shaped with recesses on thefaces in order to save material costs in fabrication.

The mobile shopping bag of the present invention is realized by theplatform insert 2 set onto the base of the opened sack 1 either placedthere by an assembler/user or pre-adhered in manufacture. Thepress-fitting mount 8 is then pressed against/through the sack 1 at itsbottom end, into a corresponding hole 3 in the platform 2. An assembledresult is illustrated by FIG. 4. The press-fitting mounts 8 may or maynot penetrate the bottom of the sack 1, (FIG. 5) but either way the sack1 material serves to frictionally secure the mounts 8 into the sackbase.

A disposable mobile shopping bag of the present invention is accordinglyquickly assembled, ready to be towed/trundled on ground surfaces, asdepicted in FIG. 6. Loads in the mobile shopping bag are thus borne bythe platform 2, distributed evenly through the forks 9 to the short,rigid axles 11 carrying the wheels 10.

If the platform insert 2 is foldable, it would be inserted withtold-break down. The holes 3 for receiving the wheel mounts 8 can beshaped such that the mounts 8 can only be pressed into the holes 3 inone direction, as FIG. 4 shows. This ensures that the user has insertedthe platform 2 in the correct orientation in the sack 1.

The snap-in/press-fitting wheel assemblies 7 can be packaged separatelyto be available for assembly, or may, for example, be manufacturedattached to the platform insert 2 for packaging and shipping, to bebroken away from the platform 2 for assembly by the user. The platform 2may be provided separately and inserted into the sack 1 for assembly atthe store, either beforehand by the store personnel, or by the shopper.

It will be understood that at minimum a pair of wheel assemblies 7press-fitted into the holes 3 unilaterally is necessary to embody theinvention properly, while a configuration using four wheel assemblies 7is described in the foregoing. Furthermore, the holes 3 may be providedin the platform to lend the user the option of wheel assemblies 7installed in various locations/numbers. The holes 3 in the platform forreceiving the press-fitting mounts of the

What is claimed is:
 1. A mobile bag assembly comprising: a shopping sackof a disposable material having a bottom-end fold made such that whenthe sack is in a fully opened position, the sack is formed with asubstantially planar base portion; a platform made of a synthetic resinpolymer material and formed with at least two holes extendingtherethrough, the platform being configured to fit within the shoppingsack and overlie the base portion when placed therein while the sack isin the fully opened position; and at least two wheel assemblies, eachwheel assembly including an inverted U-shaped fork member havingdepending leg portions for rotatably mounting a wheel therebetween and amounting assembly formed by two members extending upwardly from acentral portion of the U-shaped member, the two members having enlargedportions at upper ends thereof extending outwardly in opposed directionstherefrom and the two members being flexible for permitting flexing ofthe two members relative to the U-shaped member, wherein the mobile bagis assembled by placing the platform within the sack and against thebase portion of the sack while in the fully opened position andinserting the mounting assembly of each wheel assembly into a bottomopening of a respective hole in the platform while also pressing aportion of the sack material into the hole, the mounting assembly beinginserted into the hole until the enlarged portions on the upper ends ofthe two members are positioned above an upper surface of the platformand outwardly of a perimeter of the hole, thereby locking the wheelassembly to the platform.
 2. A mobile bag assembly as set forth in claim1, wherein said platform is foldable.
 3. A mobile bag assembly as setforth in claim 1, wherein said platform is conformed with alternatingribs and recesses for reinforcing said platform.
 4. A mobile bagassembly as set forth in claim 1, wherein: said forks of said wheelassemblies are non-rotatable with respect to said mounts; and saidmounts are configured to be non-rotatable when fitted to said platform.5. A mobile bag assembly as set forth in claim 1, wherein at least fourholes are formed in said platform.